1. Field of the Invention
The present invention relates to a process and apparatus for the preparation of a single crystal of a biopolymer. More particularly, the present invention relates to a process and apparatus for preparing a single crystal of a biopolymer by growth from a solution.
2. Description of the Related Art
The preparation of a single crystal of a biopolymer such as a protein by growth from a solution is an important technique applied in protein engineering or drug design.
To induce crystallization, an aqueous solution of ammonium sulfate, methylpentanediol or polyethylene glycol is added to an aqueous solution of a biopolymer, to be crystallized, the precipitated high polymer is allowed to stand, and the formation of a crystal nucleus and growth of a crystal are effected by the solution growth method. In this connection, various methods for the precipitation of a biopolymer are known [Lecture on Biochemical Experiments, Volume 1-III, pages 6-17 published by Tokyo Kagaku Dojin in 1976].
Nevertheless, since setting of crystallization conditions must be precise, crystallization is conducted under a variety of conditions to determine the optimum conditions, and since a manual operation for finding out optimum conditions is carried out, it is difficult to maintain a good reproducibility. Accordingly, the present inventors previously proposed a method of automatically performing this operation (see Japanese Unexamined patent Publication No. 62-106000). But in this system, where a solution path is changed according to which of many crystallization conditions is used, by a valve, the dead volume of the pipe system is increased and much valuable protein sample is wasted. Accordingly, the above-mentioned system must be improved.